[binutils-gdb] Introduce gdb_interact in testsuite

[Simon Marchi <simark at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=717cf30c8230bcf1c7cc55353645bfc268a711d0

commit 717cf30c8230bcf1c7cc55353645bfc268a711d0
Author: Anders Granlund <anders.granlund@ericsson.com>
Date:   Thu Jan 22 14:33:04 2015 -0500

    Introduce gdb_interact in testsuite
    
    gdb_interact is a small utility that we have found quite useful to debug
    test cases.
    
    Putting gdb_interact in a test suspends it and allows to interact with
    gdb to inspect whatever you want. You can then type ">>>" to resume the
    test execution. Of course, this is only for gdb devs. It wouldn't make
    sense to leave a gdb_interact permanently in a test case.
    
    When starting the interaction with the user, the script prints this
    banner:
    
    +------------------------------------------+
    | Script interrupted, you can now interact |
    | with by gdb. Type >>> to continue.       |
    +------------------------------------------+
    
    Notes:
    * When gdb is launched, the gdb_spawn_id variable (lib/gdb.exp) is
      assigned -1. Given the name, I would expect it to contain the gdb
      expect spawn id, which is needed for interact. I changed all places
      that set gdb_spawn_id to -1 to set it to the actual gdb spawn id
      instead.
    
    * When entering the "interact" mode, the last (gdb) prompt is already
      eaten by expect, so it doesn't show up on the terminal. Subsequent
      prompts do appear though. We tried to print "(gdb)" just before the
      interact to replace it. However, it could be misleading if you are
      debugging an MI test case, it makes you think that you are typing in a
      CLI prompt, when in reality it's MI. In the end I decided that since
      the feature is for developers who know what they're doing and that one
      is normally consciously using gdb_interact, the script doesn't need
      to babysit the user.
    
    * There are probably some quirks depending on where in the script
      gdb_interact appears (e.g. it could interfere with following
      commands and make them fail), but it works for most cases. Quirks can
      always be fixed later.
    
    The idea and original implementation was contributed by Anders
    Granlund, a colleague of mine. Thanks to him.
    
    gdb/testsuite/ChangeLog:
    
    	* gdb.base/statistics.exp: Assign spawn id to gdb_spawn_id.
    	* gdb.base/valgrind-db-attach.exp: Same.
    	* gdb.base/valgrind-infcall.exp: Same.
    	* lib/mi-support.exp (default_mi_gdb_start): Same.
    	* lib/prompt.exp (default_prompt_gdb_start): Same.
    	* lib/gdb.exp (default_gdb_spawn): Same.
    	(gdb_interact): New.

Diff:
---
 gdb/testsuite/ChangeLog                       | 12 ++++++++++++
 gdb/testsuite/gdb.base/statistics.exp         |  2 +-
 gdb/testsuite/gdb.base/valgrind-db-attach.exp |  2 +-
 gdb/testsuite/gdb.base/valgrind-infcall.exp   |  2 +-
 gdb/testsuite/lib/gdb.exp                     | 21 ++++++++++++++++++++-
 gdb/testsuite/lib/mi-support.exp              |  2 +-
 gdb/testsuite/lib/prompt.exp                  |  2 +-
 7 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b01a4c9..faf8493 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,15 @@
+2015-01-22  Anders Granlund  <anders.granlund@ericsson.com>
+	    Simon Marchi  <simon.marchi@ericsson.com>
+
+	* gdb.base/statistics.exp: Assign spawn id to gdb_spawn_id.
+	* gdb.base/valgrind-db-attach.exp: Same.
+	* gdb.base/valgrind-infcall.exp: Same.
+	* lib/mi-support.exp (default_mi_gdb_start): Same.
+	* lib/prompt.exp (default_prompt_gdb_start): Same.
+	* lib/gdb.exp (default_gdb_spawn): Same.
+	(gdb_interact): New.
+
+
 2015-01-22  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	* gdb.compile/compile.exp (pointer to jit function): New test.
diff --git a/gdb/testsuite/gdb.base/statistics.exp b/gdb/testsuite/gdb.base/statistics.exp
index bbb0a69..dcdf5c5 100644
--- a/gdb/testsuite/gdb.base/statistics.exp
+++ b/gdb/testsuite/gdb.base/statistics.exp
@@ -24,6 +24,6 @@ if { $res < 0 || $res == "" } {
     perror "Spawning $GDB failed."
     return
 }
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 gdb_test "" "Startup time: \[0-9.\]+ \\(cpu\\), \[0-9.\]+ \\(wall\\)\r\nSpace used: \[0-9.\]+ \\(\\+\[0-9.\]+ during startup\\)" "startup time and space"
 gdb_exit
diff --git a/gdb/testsuite/gdb.base/valgrind-db-attach.exp b/gdb/testsuite/gdb.base/valgrind-db-attach.exp
index 3055d19..89db22c 100644
--- a/gdb/testsuite/gdb.base/valgrind-db-attach.exp
+++ b/gdb/testsuite/gdb.base/valgrind-db-attach.exp
@@ -41,7 +41,7 @@ if { $res < 0 || $res == "" } {
 }
 pass $test
 # Declare GDB now as running.
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 
 # GDB spawned by `valgrind --db-attach=yes' stops already after the startup is
 # executed, like with non-extended gdbserver.  It is also not correct to
diff --git a/gdb/testsuite/gdb.base/valgrind-infcall.exp b/gdb/testsuite/gdb.base/valgrind-infcall.exp
index ad81e91c..3d3fdd3 100644
--- a/gdb/testsuite/gdb.base/valgrind-infcall.exp
+++ b/gdb/testsuite/gdb.base/valgrind-infcall.exp
@@ -33,7 +33,7 @@ if { $res < 0 || $res == "" } {
 }
 pass $test
 # Declare GDB now as running.
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 
 # GDB started by vgdb stops already after the startup is executed, like with
 # non-extended gdbserver.  It is also not correct to run/attach the inferior.
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index d3a3350..a6f200f 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1444,7 +1444,8 @@ proc default_gdb_spawn { } {
 	perror "Spawning $GDB failed."
 	return 1
     }
-    set gdb_spawn_id -1
+
+    set gdb_spawn_id $res
     return 0
 }
 
@@ -1516,6 +1517,24 @@ proc default_gdb_start { } {
     return 0
 }
 
+# Utility procedure to give user control of the gdb prompt in a script. It is
+# meant to be used for debugging test cases, and should not be left in the
+# test cases code.
+
+proc gdb_interact { } {
+    global gdb_spawn_id
+    set spawn_id $gdb_spawn_id
+
+    send_user "+------------------------------------------+\n"
+    send_user "| Script interrupted, you can now interact |\n"
+    send_user "| with by gdb. Type >>> to continue.       |\n"
+    send_user "+------------------------------------------+\n"
+
+    interact {
+	">>>" return
+    }
+}
+
 # Examine the output of compilation to determine whether compilation
 # failed or not.  If it failed determine whether it is due to missing
 # compiler or due to compiler error.  Report pass, fail or unsupported
diff --git a/gdb/testsuite/lib/mi-support.exp b/gdb/testsuite/lib/mi-support.exp
index f1b9c2b..20546f6 100644
--- a/gdb/testsuite/lib/mi-support.exp
+++ b/gdb/testsuite/lib/mi-support.exp
@@ -191,7 +191,7 @@ proc default_mi_gdb_start { args } {
 	    return -1
 	}
     }
-    set gdb_spawn_id -1
+    set gdb_spawn_id $res
 
     # FIXME: mi output does not go through pagers, so these can be removed.
     # force the height to "unlimited", so no pagers get used
diff --git a/gdb/testsuite/lib/prompt.exp b/gdb/testsuite/lib/prompt.exp
index 1982524..a9696a4 100644
--- a/gdb/testsuite/lib/prompt.exp
+++ b/gdb/testsuite/lib/prompt.exp
@@ -78,7 +78,7 @@ proc default_prompt_gdb_start { } {
 	    return -1
 	}
     }
-    set gdb_spawn_id -1
+    set gdb_spawn_id $res
     return 0
 }